In the past three decades, modern medicine has gained extraordinary ground. In addition to refining our understanding of stem cells and how they function, we’ve quickly moved to bioengineering sheep and other animals from somatic cells, as well as tissues that could possibly be used for transplants. It’s seemingly the stuff of science fiction. But it’s happening; it’s called regenerative medicine. Regenerative medicine is the science of using living human cells to fight, repair, replace and/or otherwise heal damaged, diseased or decaying ones. It’s a broad term and can be applied in and for a variety of different situations and conditions. Many people may only associate regenerative medicine with sports injuries since several well-known athletes have made headlines by undergoing a stem cell treatment to help alleviate the effects of their acute or chronic injuries. But while stem cell therapy is one type of regenerative procedure, it’s not the only one. Regenerative medicine includes all of the following clinical therapies:
Stem cells are at the heart of regenerative medicine. After all, they are the body’s “master cells,” capable of making many, if not all (as in the case of embryonic stem cells), of the body’s different cell types. But other cells can be used for cell therapy, as well, including red blood cells, certain types of immune cells and islet cells. Red blood cells, for example, can be harvested to create a platelet rich plasma (PRP) and mesenchymal stem cells can be used to treat pain and inflammation for degenerative joint conditions.
Immunotherapy is a type of cellular therapy, but it also includes the transfer of certain proteins and monoclonal antibodies and/or other molecular material such as interleukins and interferons. Its goal is not so much to repair cells but to fight “bad cells.” It does this by either strengthening the body’s overall immune system so that it can fight a disease (usually cancer) on its own or by creating an “army of cells” specifically programmed to target certain “bad” cells (like those in a tumor). In either case, specific immune cells are harvested from a donor, grown and/or modified in a lab and then injected into a patient to effectuate healing.
Transplantation and Bioengineering
Finally, regenerative medicine can also refer to those treatments that aim to replace or repair large areas of damaged tissue (like organs, large portions of the skin and bone marrow). A traditional organ transplant, for instance, is a type of regenerative procedure. Indeed, some transplants are also stem cell transplants, such as when bone marrow and its accompanying hematopoietic stem cells are harvested and then transplanted into a recipient to treat leukemia. And sometimes, tissues can be manufactured using living cells so that they can be transplanted into a body to provide a conducive environment for cell proliferation and growth. Examples of this include using bone grafts to treat cancerous or badly broken bones or growing artificial skin to cover severe burns.
Nivolumab, an immunotherapy drug, has been described as a potential “game-changer” in promising results presented at the European Cancer Congress.
In a study of head and neck cancer, more patients taking the drug survived for longer compared with those who were treated with chemotherapy.
In another study, combining nivolumab with another drug shrank tumors in advanced kidney cancer patients.
Immunotherapy works by harnessing the immune system to destroy cancer cells.
Advanced head and neck cancer has very poor survival rates.
In a trial of more than 350 patients, published in the New England Journal of Medicine, 36% treated with nivolumab (Opdivo) were alive after one year compared with 17% who received chemotherapy.
Patients also experienced fewer side effects from immunotherapy.
The benefits were more pronounced in patients whose tumors had tested positive for HPV (human papillomavirus). These patients survived an average of 9.1 months with nivolumab and 4.4 months with chemotherapy.
Normally, this group of patients are expected to live less than six months.
Early data from a study of 94 patients with advanced kidney cancer showed that the double hit of nivolumab and ipilimumab resulted in a significant reduction in the size of tumors in 40% of patients.
Of these patients, one in 10 had no sign of cancer remaining.
This compares with 5% of patients showing tumor reduction after standard therapy.
Nivolumab and ipilimumab both work by interrupting the chemical signals that cancers use to convince the immune system they are healthy tissue.
Researchers have found that a genetically-engineered version of the cold sore virus (herpes simplex virus) could treat skin cancer.
T-Vec, the modified herpes virus, is harmless to normal cells but when injected into tumors it replicates and releases substances to help fight the cancer.
The findings, published in the Journal of Clinical Oncology, show the therapy could lengthen survival by years – but only for some melanoma patients.
The treatment is not yet licensed.
Similar “immunotherapy” treatments for melanoma are already available in the US and in Europe, but researchers believe T-Vec would be a welcome addition to these.
It would also be the first melanoma treatment that uses a virus.
The latest study is the largest ever randomized trial of an anti-cancer virus and involved 436 patients from 64 centers in the US, the UK, Canada and South Africa who had inoperable malignant melanoma.
UK trial leader Prof Kevin Harrington, from the Institute of Cancer Research, London, said: “There is increasing excitement over the use of viral treatments like T-Vec for cancer, because they can launch a two-pronged attack on tumors – both killing cancer cells directly and marshalling the immune system against them.
“And because viral treatment can target cancer cells specifically, it tends to have fewer side effects than traditional chemotherapy or some of the other new immunotherapies.”
Although it has not yet been licensed, doctors are excited about the very real prospect of a brand new type of treatment for advanced melanoma – and, in the future, possibly other cancers too.
The idea of using viruses to enter and kill cancerous cells has been gathering scientific pace and kudos.
This latest study in the Journal of Clinical Oncology is the largest ever randomized trial of an anti-cancer virus and provides tantalizing evidence that the treatment concept could soon be moved into the clinic, after decades of work in the lab.
Researchers now want to do more studies to identify which patients might benefit from the treatment and whether it should be used alongside other melanoma drugs that are already approved.
Drug regulators will be watching closely and will soon make a final decision about T-Vec.
Damage to the skin by the sun’s harmful UV rays increases your risk of developing this cancer.
According to a recent study, an antibody drug which makes a wide range of cancers more vulnerable to the body’s immune system is “exciting” and may mark a new era.
The new drug strips cancer cells of the “camouflage” they use to evade attack by the immune system.
In the most detailed study, published in Nature, some patients completely recovered from terminal bladder cancer.
The immune system is in delicate balance with some chemicals in the body encouraging a strong vigorous response, while others try to dampen it down.
Tumors can hijack this system to hide from the immune system.
One trick which tumors use is a protein called PD-L1 which is normally used to prevent autoimmune diseases.
An international team of scientists has been trialing a drug to block PD-L1, produced by the company Roche, on 68 people with advanced bladder cancer.
All the patients had tried chemotherapy and had been given six-to-eight months to live.
More than half the patients, whose tumors were using PD-L1 to hide from the immune system, showed signs of recovery.
In two patients there were no signs of cancer after the treatment.
One in ten patients responded to the experimental therapy even if PD-L1 was not present in the tumor.
Dr. Tom Powles, an oncologist at the Barts Cancer Institute at Queen Mary University of London and part of the research team, said: “There have been no new drugs for bladder cancer for 30 years.
“The tumors have developed a camouflage layer, PD-L1, and by removing the camouflage the tumor becomes identifiable.
“A subgroup of patients seems to do exceptionally well.”
Dr. Tom Powles is funded by the UK’s National Health Service (NHS) and receives no money from Roche.
The drug has been given “breakthrough therapy” status in the US and could be used widely by patients there at the end of 2015, if a larger trial shows the same results.
Much larger randomized clinical trials would be needed in order for the experimental therapy to be used in Europe.
A similar set of trials to boost the immune attack revealed at the American Society of Clinical Oncology conference in Chicago in June, showed similar therapies could improve survival in advanced skin cancer.
In a trial of 411 patients evaluating a drug, pembrolizumab – 69% of patients survived at least a year.
Those results were described as having the “potential to be a paradigm shift for cancer therapy”.
A separate study of 175 patients, led by Yale University in the US, showed responses to the drug in patients with non-small cell lung cancer, melanoma, renal cell carcinoma and other cancers.